Abstract:Microstructure and mechanical properties of 2219-T87 high-strength aluminum alloy weld joints are investigated based on the conventional VP-TIG and ultrafast-convert hybrid ultrasonic pulse VPTIG (HPVP-TIG) welding technology. The results show that the number of gas pore in welds obtained by the HPVP-TIG welding process is predominantly reduced and eliminated indeed. The grain structure is refined and the mechanical properties of weld joint are signifi cantly enhanced. Under the conditions of pulse frequency of 40 kHz, pulse duty of 20% and pulse current amplitude of 100 A, tensile strength and percentage elongation increase about 32% and 138%, respectively by compare it with the conventional,VPTIG process.